This invention relates to the field of motion transference gearing and in particular to clutch operated gear sets for transferring bicycle pedaling action from the front gear sprocket to the rear drive sprocket.
The gearing necessary to transfer the pedaling motion a rider of a bicycle into the forward motion of that bicycle is well known in the art. Such gearing has spans from the single ratio, two-sprocket system to the more recent complicated 10 & 15 derailleur systems used on many current bicycles gearing assemblies.
The very early bicycles, in their most simple design, were of direct transfer. That is, forward pedaling caused the bicycle to move in a forward direction, while rearward pedaling caused the bicycle to move in a rearward or reverse direction. This drive action was and is unsatisfactory for any number of reasons. One principal reason being that the bicycle would need to be constantly pedaling in order to continue moving forward. Also, if the rider elected to stop applying pressure to pedal the bicycle, the forward momentum of the bicycle would still cause the bicycle to move forward and the pedals to continue rotating.
To help address this problem and to provide a partial solution, gearing systems have been developed. The gearing system are used to transfer the rider's rotary pedaling motion into rear-wheel forward motion. With a two-sprocket bicycle gearing system, the pedaling action of the front drive sprocket is transferred to the rear free wheel sprocket cluster on the rear-wheel by means of a drive chain or other suitable transfer method. The teeth on the sprockets engage the openings in the chain to transfer the motion.
While this drive system was an improvement in the drive delivery, a primary advance was made with the ratcheting of the rear gearing system into the free wheel sprocket cluster, allowing the bicycle rear wheel to continue rotating forward while the forward sprocket gear and drive chain remain stationary. This system still allows the drive chain to impart forward motion to move the bicycle in a forward direction by forward pedaling.
In the prior art gear systems, the braking mechanism is usually located in the rear axle bearing assembly. In this style of bicycle, moving the pedal in a "backward" would engage the rear brake thereby stopping the rear wheel rotation and the bicycle forward motion. With multi-gear bicycles, the braking is usually done by hand brakes which engage pads that apply pressure to the rim of the tire thereby stopping the bicycle. On these bicycles, rearward pedaling is free-action, neither engaging a braking system or causing the bike to move in a rearward direction.
These basic designs have been well known in the arts for decades. However, significant work has nonetheless gone into the design of more efficient and smoother gear-shift mechanisms, shifting systems, and design of sprocket and chain meshing.
For example, with a two-sprocket system, the gearing is set in the mid-range for average operation. However, for ease of pedaling, multi-gears are used to step up or down the rider's pedaling motion. With multi-gear bicycling systems, the gears allow for a wide-range of pedaling forces. This provides easier initial pedaling prior to the build-up of momentum and for greater relative distance of travel once momentum and speed have been achieved. Traditionally, such multi-gear bicycles have two gears of different diameters on the front sprocket and five on the rear axle. Shifting is accomplished by a set of guides which laterally move the chain between adjacent gears.
All of the presently available systems have one thing in common. That is, the bicycle is adapted such that the drive gears are engaged for forward motion when the rider pedals in a "forward" direction. By forward, it is meant that when the pedal is in its upper-most position, that pedal must be pushed in a forward and a down-ward direction in order for the bicycle to go forward. However, all of the previously recited gearing systems have a single point in common. That is, that the gearing is arranged such that the bicycle will be moved in a forward direction when pedaling is in a forward direction, but that no forward movement is created by rearward pedaling. With either gearing mechanism, when the bicycle is in forward motion, the bicycle will continue in said motion when the pedaling is stopped and the rear wheel is allowed to ratchet with regard to the rear sprocket gear.
Having established same, it is understood that bicycling provides excellent exercise opportunities. Accordingly, bicycling for exercising and recreation has enjoyed popular support for both recreation, sports, and practical travel purposes. Forward pedaling provides the rider with much needed exercise opportunities.
It should be noted that advantageously, a different set of muscles are used in rear pedaling. Thus for a full exercise routine, for complete rehabilitation of the leg muscles, or to delay the onset of fatigue, a system that would allow both front and back pedaling would be desireable. The present invention provides just that ability.
There is no reason why mechanically the rider could not pedal backwards and still have the bicycle engaged in forward motion. Tradition and the normal anatomical arrangement has generally resulted in the forward pedaling to generate forward motion. However, because there is no mechanical reason for pedaling backwards, there is no reason why same can not be accomplished. Nonetheless because the tradition is to pedal forward, there have not be any bicycling systems established which allow for forward motion with pure backward pedaling.
It should be understood however: that "backward pedaling" will also provide the rider with advantageous exercise opportunities and in fact the rearward pedaling causes the riders to use a different set of muscles that are ordinary used then when pedaling in a forward direction. This fact has been used on several exercise bicycles which allow for resistance to motion in both the forward and rearward pedaling motion. However, to date the ability to pedal forward and backward with the same bicycle traveling in a forward direction has not been available. It is for this purpose that the present invention is directed.
What is needed therefore is a bicycle gearing system which will allow the bicycle to maintain forward motion while selectively pedaled in either a forward or in a rearward direction.
It is the objective of this invention to allow forward motion of the bicycle when the bicycle is pedaling in a rearward direction.
It is another objective of this invention to allow forward motion of the bicycle when the bicycle is selectively pedaling in a forward or rearward direction.